This invention relates to a plasma processing apparatus for processing a workpiece by applying a high-frequency bias voltage to the workpiece by use of a plasma, a protecting layer for plasma processing apparatus provided in the processing chamber of the plasma processing apparatus, and a method for installing the protecting layer.
Apparatus such as that disclosed in JP-A-2001-57361 have been known as a plasma processing apparatus for processing a workpiece by applying a high-frequency bias voltage to the workpiece by use of a plasma. The apparatus disclosed in the above reference is as follows.
An antenna capable of emitting electromagnetic waves is provided in the upper part of a plasma processing chamber. A bottom electrode for setting a wafer thereon as a workpiece is provided in the lower part of the plasma processing chamber. A processing gas introduced into the plasma processing chamber is made into plasma by the interaction between electromagnetic waves emitted by the antenna and a magnetic field created by a magnetic-field-creating means. A wafer is subjected to etching treatment by controlling ions and radicals in the plasma by adjusting a bias electric power applied to the antenna and a bias electric power applied to the bottom electrode. For the etching treatment, a mixed gas containing a fluorocarbon type gas is used as the treating gas. Thus, a silicon dioxide film is etched.
A 2-mm thick sidewall sleeve composed of a resin layer of a polyether imide or the like is provided on the inner wall of the plasma processing chamber so as to be removable. Thus, contamination with a metal from a metal wall surface constituting the plasma treating chamber is prevented, and carbon-containing deposits are stably accumulated on the resin layer to suppress the production of contaminants.
As another prior art using a resin in order to prevent the contamination, that disclosed in the specification of U.S. Pat. No. 4,397,724 (JP-B-4-62170) can be exemplified. This reference discloses that a wafer is subjected to etching treatment after being mounted in a reactor at least some of the inner surfaces of which have been coated with a polyarylate polymer, and that a thickness of the coating of about one-sixteenth inch is advantageous.